The invention relates to a photometric process using a corresponding computer controlled spectrophotometer.
A computer controlled photometer of the type involved here is, for example, the portable spectrophotometer SPM 100 of the Gretag AG, Regensdorf, Switzerland, which is in worldwide use. This spectrophotometer supports a plurality of measuring modes (color densities, spectra, colorimetrics, etc.), makes possible measurements under different conditions (standards for color densities, types of light, observer angles for colorimetrics) and also permits free programming of these conditions (for example, types of light). It is further capable of setting and storing several reference and calibrating values.
The operation of the instrument, i.e., the choice of the different measuring modes and conditions and the setting and storage of the different reference and calibration values, etc. is normally carried out manually using the operating keyboard of the instrument. Additionally, a serial interface is provided for the connection of an external computer, through which the instrument may be alternatively controlled by the transmission of the corresponding control data.
As the above-mentioned photometer is a portable, relatively small, manual instrument, the memory and operating possibilities are naturally subject to certain limitations, which in particular often appear to make the entry of complex data via the keyboard cumbersome.